Virtually all modern electronic devices are made with integrated micro-electronic circuit devices. These devices are generally formed on a wafer or substrate using multiple processing steps. Some of these processing steps are performed by heating the wafer. For example, rapid thermal anneal and furnace anneal are processes performed by heating a wafer to change its electrical properties. Different heat treatments (varying in time, temperature profiles, process gases, etc.) are used to provide different effects. These heating processes may be used to activate dopants, change film interfaces, densify deposited films, change states of grown films, repair damage from ion implantation, move dopants or drive dopants from one film into another or from a film into the wafer substrate. Other thermal processes include polyimide bake, lead free reflow, metal anneal, vacuum drying, photoresist bake and low-k bake.
While different temperatures and temperature profiles are used in different thermal processes, many of these thermal processes require heating the wafers to 500° C. or even higher. Operation in these temperature ranges generally requires high capacity heating elements, extensive insulating and cooling elements, and sufficient clearance around the thermal processor to avoid affecting adjacent objects, equipment, or people. As a result, thermal processors, and especially batch thermal processors, have conventionally been provided as relatively large and independent apparatus or systems dedicated to performing only thermal processing.
The high operating temperatures of thermal processors of course creates various problems when trying to provide a single system having a thermal processor and other types of processors. However, notwithstanding the heat related effects within a processing system, the thermal processor itself must be able to provide reliable, controllable, and substantially uniform wafer heating. Consequently, these requirements may tend to conflict with system requirements, such as size limitations, heat up/cool down cycle time requirements, loading/unloading parameters, etc. Accordingly, there is a need for a thermal processor having improved performance. There is also a need for a thermal processor that may be used in a processing system having other types of processors.